SPECIFIC AIMS 1. Continue to develop new genetically altered animal models for studying mechanisms of the biology of aging. 2. Provide a resource that enables University of Washington Health Sciences faculty involved in various aging projects to utilize genetic engineering technology for answering basic questions about the biology of aging. 3. Provide a resource and expertise in the construction of targeting vectors, injectable DNA constructs and inducible promoters systems for generating genetically altered animal models of the biology of aging. 4. Accelerate and enhance cryopreservation of embryos and sperm from useful genetically altered mouse models of aging for repository storage and conservation of housing resources. 5. Provide a training resource for fellows and junior faculty in transgenic and embryonic stem cell technology.